Metallic terminal for electrodes.



G. M. LITTLE.

METALLIC TERMINAL FOR ELECTRODES.

APPLICATION FILED AUG. 1 h 1913.

Patented Nov. 13, 1917.

yYENTER ATTORNEY I Lil? WITNESSES:

UNITED STATES PATENT oF IoE.

cEonoE m. LITTLE, or rrr'rsnunon, PENNSYLVANIA, assrenon r0 wEs'rmcnousE ELEc'rEIc Ann manumcruame comramr, A conroaazrron' or ramcenvmm.

' METALLIC \TEBMINAL Eon E EcraonEs.

Specification of Letters ratent. at t my 13, 1917,

Application filed August 11, 1913. Serial No. 781,031.

To all whom it may concern:

Be it known that I, GEORGE M. Lrr'rm, a. citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Metallic Terminals for Electrodes, :ofwhich' the followingis a specification.

My invention relates to electrical connectors, and it has particular reference to contact terminals for electrodes which are employed in arc lamps. These terminals,

whenused in conjunction with electrodes of lead, is cast integrally up0n the end of the wire which projects from the non-consumable end of the electrode. The metallic wire within the electrode decreases the resistance to the passage of current through the electrode. The metallic cap provides a metallic contact, and, consequently, good electrical connection between the electrode so equipped and the cooperatively engaged conducting members of the lamp circuit. When this electrode is consumed in the arc, it is replaced by anew electrode which is provided with an integrally cast metal cap similar to that above-mentioned. The expense of this replacement is an important item in the maintenance cost of an electric arc lamp.

One object of my invention is to provide aconducting terminal which may be used with a plurality of electrodes. It is necessary to furnish only one terminal for each arc lamp, thereby materially reducing the maintenance cost of the lamp.

Another object of my invention is to provide a metal terminal of the character indicated which will be durable, and the first cost of which will be low.

For a better understanding of the nature, the scope and the characteristic features of my invention, reference may be had to the following description and accompanying drawing forming a part hereof, in which Figure l is a side view, partially in section, of a portion of .an arc lamp, an electrode of which engages a device embodying a form of my invention; Fig. 2 is a sectional view of the electrode and a cooperatively engaged metal cap which are shown inFig. 1; F1g. 3 1s a view of the top of the metal cap; Flg. A is a side view of the metal cap; Fig. 5 1s a view of the bottom of the cap;

' Figs. .6, 7, 8 and 9 show diflerent views of a metal cap ,modified from the form which. is shown in Fig. 2, the modification being constructed inv accordance with my invent on, and Fig. 10 is a view, partiallv in sect1on, of a modification ofthe arrangement shown in Fig. 1.

Referring to Fig. 1, a consumable electrode 1 of a metallic flaming arc lamp of a standard type of construction (a portion of the internal mechanism of the lamp being shown in the drawing) engages a metal cap 2 which embodies a form of my invention. The electrode is held in its operating position by a clutch 3 which is connected by a clutch rod 4 of an armature (not shown) of the feedingmagnets of the lamp.

Current, flowing through the electrode 1, passes through the metal cap 2 which is embraced by a metallic sheath 5 constituting an extension of a metallic member 6. A flexible conductor 7, which is wound in the form of a" helix and adapted to encircle a guiding member 8 as the electrode 1 moves up or down, is electrically connected to the contact member 6 substantially as shown'in the drawing. A tube 9 serves as a guide for the conductor 7, the electrode 1 and the members cooperatively engaged therewith.

A metallic member or wire 10, centralcli-y positioned within the electrode 1, exten s from the consumable end of the electrode and projects from its upper end. The metal cap 2, being provided with a central opening 11, engages this projecting portion of the wire 10, thereby insuring a good electrical connection between the said electrode and the metal cap. As shown in Fig. 2, the opening 11 comprises two 'dilferent bores, the lower portion being a bore of a diameter smaller than that of the upper portion. I Inasmuch as the diameter of the w1re 10 approximates that of the bore at the lower portion of the opening 11, the wire, after being inserted for a short distance-in the opening 11, will tend to bind because of irregularities in its dimensions,

ameter, and thereby will prevent the forming of a satisfactory electrical contact between the cap 2 andthe electrode 1. In order to preclude the wire from binding in the opening 11, the bore of the upper half of the opening has a diameter larger than that of the lower half of the said opening. a

As the cap 2 is adapted for cont nuous use, the gripping portion of the opening 11 will wear as new electrodes are supplied to the lamp for replacing the consumed electrodes. Again, the projecting portion of the wire 10 is not always uniform in diameter in all the.electrodes that may be supplied to the lamp. To insure against insuflicient gripping action between the .projection of the wire 10 and the cap 2, I have provided the cap 2 with a plura ity of Iongitudinally extending saw-cuts, by means of which a spring or resilient action 1s obtained for yieldingly engaging the electrode and the cap. 4

As shown in the drawing, saw-cuts 12 are made in the upper portion of the cap 2 in close proximity to, and on each side of the opening 11, the said saw cuts extending downwardly for about one-half of the total length of the cap 2. A diametral saw-cut 13, passing through the opening 11 of the cap 2, extends from the bottom of the cap to within a short distance of the top, in order to accentuate the spring action, as supplied by additional saw-cuts 14 that are positioned laterally to the opening 11 and extend from the bottom of the ca up to the point where the diameter 0 the bore of the opening 11 changes. The sawcuts 1 1 may be made substantially at right angles to one another, as shown in Fig. 5, or, if a high degree of resilient action in the cap is not desirable, the said saw-cuts may be made as shown in Fig. 9. It will be understood that the positioning and the length of the above-mentioned saw-cuts may be varied considerably from those shown and described, the desirability of such cuts being to furnish a suitable spring action as the metal cap 2 grips the projecting portion of the wire 10.

When an electrode is withdrawn from the arc lamp, the cap 2, with the sheath 5, will be drawn downwardly and outwardly extending flare 15 formed around the lower periphery of the cap 2 prevents the cap from being drawn through an opening 16 in the clutch 3. At the same time, the cap 2 may be easily forced upwardly through the opening 16 by means of the contracting .of

I v the lower portion of the cap 2, which results from the saw cuts 13 and 14 being properly made. The flare 15 also assists in retaining the cap in the metallic sheath 5 because the flare eifects a firm engagement between the cap and the sheath, the internal diameter of the engaging electrode into proper mechanical and electrical contact.

In Fig. 10, the metal ca 2 is shown as secured to the guiding mem er 8 by means of to the G5 the threaded extension 18 which is formed upon the member 8. The projecting por tion of the wire 10 extending into the central opening of the member 2, provides means for detachably engaging the electrode 1 and the metal cap 2. As previously'exlained, the saw cuts 13 and 14 and the diferent bores of the central opening 11 provide means whereby the pro ecting portion of the wire 10 may be yieldingly engaged by the cap 2 and may also be easily disengaged when replacing the burned electrode.

While I have herein described specific embodiments of my invention, it is not intended that the invention, in all its aspects, shall be limited to these particular embodiments, as it will be apparent to anyone skilled in the art that changes may be made within the scope of the appended claims.

I claim as my invention:

1. In an arc lamp, the combination with an electrode having an embedded central conducting core which projects from its upper end, of a metallic terminal therefor pro-- vided with a longitudinallyextending open ing having a plurality of different diameters and slits extending inwardly from each end thereof, thereby permitting. said terminal to yieldinglyengage said projecting portion of the core.

2. In an arc lamp, the combination with an electrode having an embedded metallic member which projects from its upper end, of a conducting terminal therefor provided with a longitudinally extending opening and slits extending inwardly from each end thereof, thereby'imparting resilient action to said terminal so as to yieldingly engage said projecting portion of the embedded metallic member.

3. In an arc lamp, the combination with an upright electrode having an embedded conducting core which projects from its upper end, of a metallic terminal therefor provided with a succession of longitudinally ex-' tending openings of different diameters and slits extending inwardly from each end thereof, said terminal being so disposed that the smallest diameter opening is immediately adjacent to said electrode.

4. In an arc lamp, the combination with an electrode having an embedded core that extends beyond its upper end, of a terminal lot therefor provided with a longitudinally exsubscribed my name this 30th dayof July, tending opening which has a plurality of 1913. different diameters and saw-cuts which extend inwardly from one of the ends there- GEORGE LITTLE 5 of and a flaring end for limiting the longi- Witnesses: tudinal movement of the said electrode. B. B. HINEs,

In testimony whereof, I have hereunto 'M. C. MERZ- 

